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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "TraversalRule.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/a11y/Accessible.h"
#include "mozilla/a11y/Role.h"
#include "HTMLListAccessible.h"
#include "SessionAccessibility.h"
#include "nsAccUtils.h"
#include "nsIAccessiblePivot.h"
using namespace mozilla;
using namespace mozilla::a11y;
TraversalRule::TraversalRule()
: TraversalRule(java::SessionAccessibility::HTML_GRANULARITY_DEFAULT,
true) {}
TraversalRule::TraversalRule(int32_t aGranularity, bool aIsLocal)
: mGranularity(aGranularity), mIsLocal(aIsLocal) {}
uint16_t TraversalRule::Match(Accessible* aAcc) {
MOZ_ASSERT(aAcc);
if (mIsLocal && aAcc->IsRemote()) {
// If we encounter a remote accessible in a local rule, we should
// ignore the subtree because we won't encounter anymore local accessibles
// in it.
return nsIAccessibleTraversalRule::FILTER_IGNORE |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
} else if (!mIsLocal && aAcc->IsLocal()) {
// If we encounter a local accessible in a remote rule we are likely
// traversing backwards/upwards, we don't ignore its subtree because it is
// likely the outer doc root of the remote tree.
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t result = nsIAccessibleTraversalRule::FILTER_IGNORE;
if (nsAccUtils::MustPrune(aAcc)) {
result |= nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
uint64_t state = aAcc->State();
if ((state & states::INVISIBLE) != 0) {
return result;
}
if (aAcc->Opacity() == 0.0f) {
return result | nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
switch (mGranularity) {
case java::SessionAccessibility::HTML_GRANULARITY_LINK:
result |= LinkMatch(aAcc);
break;
case java::SessionAccessibility::HTML_GRANULARITY_CONTROL:
result |= ControlMatch(aAcc);
break;
case java::SessionAccessibility::HTML_GRANULARITY_SECTION:
result |= SectionMatch(aAcc);
break;
case java::SessionAccessibility::HTML_GRANULARITY_HEADING:
result |= HeadingMatch(aAcc);
break;
case java::SessionAccessibility::HTML_GRANULARITY_LANDMARK:
result |= LandmarkMatch(aAcc);
break;
default:
result |= DefaultMatch(aAcc);
break;
}
return result;
}
bool TraversalRule::IsSingleLineage(Accessible* aAccessible) {
Accessible* child = aAccessible;
while (child) {
switch (child->ChildCount()) {
case 0:
return true;
case 1:
child = child->FirstChild();
break;
case 2:
if (IsListItemBullet(child->FirstChild())) {
child = child->LastChild();
} else {
return false;
}
break;
default:
return false;
}
}
return true;
}
bool TraversalRule::IsListItemBullet(const Accessible* aAccessible) {
return aAccessible->Role() == roles::LISTITEM_MARKER;
}
bool TraversalRule::IsFlatSubtree(const Accessible* aAccessible) {
for (auto child = aAccessible->FirstChild(); child;
child = child->NextSibling()) {
roles::Role role = child->Role();
if (role == roles::TEXT_LEAF || role == roles::STATICTEXT) {
continue;
}
if (child->ChildCount() > 0 || child->ActionCount() > 0) {
return false;
}
}
return true;
}
bool TraversalRule::HasName(const Accessible* aAccessible) {
nsAutoString name;
aAccessible->Name(name);
name.CompressWhitespace();
return !name.IsEmpty();
}
uint16_t TraversalRule::LinkMatch(Accessible* aAccessible) {
if (aAccessible->Role() == roles::LINK &&
(aAccessible->State() & states::LINKED) != 0) {
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t TraversalRule::HeadingMatch(Accessible* aAccessible) {
if (aAccessible->Role() == roles::HEADING && aAccessible->ChildCount()) {
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t TraversalRule::SectionMatch(Accessible* aAccessible) {
roles::Role role = aAccessible->Role();
if (role == roles::HEADING || role == roles::LANDMARK ||
aAccessible->LandmarkRole()) {
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t TraversalRule::LandmarkMatch(Accessible* aAccessible) {
if (aAccessible->LandmarkRole()) {
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t TraversalRule::ControlMatch(Accessible* aAccessible) {
switch (aAccessible->Role()) {
case roles::PUSHBUTTON:
case roles::SPINBUTTON:
case roles::TOGGLE_BUTTON:
case roles::BUTTONDROPDOWN:
case roles::COMBOBOX:
case roles::LISTBOX:
case roles::ENTRY:
case roles::PASSWORD_TEXT:
case roles::PAGETAB:
case roles::RADIOBUTTON:
case roles::RADIO_MENU_ITEM:
case roles::SLIDER:
case roles::CHECKBUTTON:
case roles::CHECK_MENU_ITEM:
case roles::SWITCH:
case roles::MENUITEM:
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
case roles::LINK:
return LinkMatch(aAccessible);
case roles::EDITCOMBOBOX:
if (aAccessible->State() & states::EDITABLE) {
// Only match ARIA 1.0 comboboxes; i.e. where the combobox itself is
// editable. If it's a 1.1 combobox, the combobox is just a container;
// we want to stop on the textbox inside it, not the container.
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
break;
default:
break;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}
uint16_t TraversalRule::DefaultMatch(Accessible* aAccessible) {
switch (aAccessible->Role()) {
case roles::COMBOBOX:
// We don't want to ignore the subtree because this is often
// where the list box hangs out.
return nsIAccessibleTraversalRule::FILTER_MATCH;
case roles::EDITCOMBOBOX:
if (aAccessible->State() & states::EDITABLE) {
// Only match ARIA 1.0 comboboxes; i.e. where the combobox itself is
// editable. If it's a 1.1 combobox, the combobox is just a container;
// we want to stop on the textbox inside it.
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
break;
case roles::TEXT_LEAF:
case roles::GRAPHIC:
// Nameless text leaves are boring, skip them.
if (HasName(aAccessible)) {
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
break;
case roles::STATICTEXT:
// Ignore list bullets
if (!IsListItemBullet(aAccessible)) {
return nsIAccessibleTraversalRule::FILTER_MATCH;
}
break;
case roles::HEADING:
case roles::COLUMNHEADER:
case roles::ROWHEADER:
case roles::STATUSBAR:
if ((aAccessible->ChildCount() > 0 || HasName(aAccessible)) &&
(IsSingleLineage(aAccessible) || IsFlatSubtree(aAccessible))) {
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
break;
case roles::GRID_CELL:
if (IsSingleLineage(aAccessible) || IsFlatSubtree(aAccessible)) {
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
break;
case roles::LABEL:
if (IsFlatSubtree(aAccessible)) {
// Match if this is a label with text but no nested controls.
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
}
break;
case roles::MENUITEM:
case roles::LINK:
case roles::PAGETAB:
case roles::PUSHBUTTON:
case roles::CHECKBUTTON:
case roles::RADIOBUTTON:
case roles::PROGRESSBAR:
case roles::BUTTONDROPDOWN:
case roles::BUTTONMENU:
case roles::CHECK_MENU_ITEM:
case roles::PASSWORD_TEXT:
case roles::RADIO_MENU_ITEM:
case roles::TOGGLE_BUTTON:
case roles::ENTRY:
case roles::KEY:
case roles::SLIDER:
case roles::SPINBUTTON:
case roles::OPTION:
case roles::SWITCH:
case roles::MATHML_MATH:
// Ignore the subtree, if there is one. So that we don't land on
// the same content that was already presented by its parent.
return nsIAccessibleTraversalRule::FILTER_MATCH |
nsIAccessibleTraversalRule::FILTER_IGNORE_SUBTREE;
default:
break;
}
return nsIAccessibleTraversalRule::FILTER_IGNORE;
}